Development and characterization of pressure-sensitive paint with high sensitivity and constancy in rarefied gas environments

Accurate measurement of the surface pressure distribution of spacecraft models under low-pressure conditions contributes to the optimal design of space probes. Pressure-Sensitive Paint (PSP) is a non-contact technique for optical measurement of full-field surface pressure distribution. To apply the PSP technology in rarefied gas environments, PSP with high pressure sensitivity and high pressure sensitivity constancy at low pressures needs to be developed. This paper uses PdTFPP, a luminophore with long luminescence life, Room-Temperature Vulcanized (RTV) silicone rubber, a polymer with high oxygen permeability, and micro-nano-particles with different types and contents to develop pressure-sensitive paints. The influences of the particle type, particle contents, and dispersants on the static performances of the PSP are investigated. Experimental results indicate that the Polymer-Ceramic Pressure-Sensitive Paint (PC-PSP), employing mesoporous silica (mSiO₂) as the micro-nano-particles, exhibits higher pressure sensitivity and lower photodegradation rate compared to other micro-nano-particles. PdTFPP/mSiO₂-RTV, with a particle content of 70wt% and prepared without dispersant, has a pressure sensitivity and pressure sensitivity constancy of 80.72%/kPa and 99.44%, respectively, and its temperature sensitivity and photodegradation rate are −0.9%/K and −0.09%/min, respectively. In comparison to other PSP based on highly oxygen permeable polymers, PdTFPP/mSiO₂-RTV (70wt%) is demonstrated to be more suitable for static small pressure measurements in low pressure environments.